1. Field of the Invention
The present invention relates generally to the selection of optical fibers and, more specifically, to the selection of optical fiber reels from inventory to fill an order, such as an order for a cable or a cabled system.
2. Technical Background
When an optical fiber is produced, the optical fiber is generally placed on a reel for storage within a warehouse, prior to shipment to a customer. Before the optical fiber reel is stored in the warehouse, however, various optical parameters of the optical fiber reel are normally recorded. When a customer order is received for optical fibers, optical fiber reels are generally selected so that when the optical fiber reels are assembled into final cabled systems (e.g., submarine cables), customer requirements on the optical specifications may be met at constituent, span, cable, cabled segment, and cabled system levels. For example, a customer order for a cabled system may include 2 cabled segments, each cabled segment including 8 cables, each cable including 16 spans, each span including 5 constituents, wherein the constituents are individual reels of optical fiber. However, because of the number of different customer requirements and their stringency, many optical fiber reels fail to individually meet all of the customer requirements. By judiciously selecting optical fiber reels for use in a span, cable, or cabled segment, optical specifications can be tightened, thus, increasing a guardband and reducing variability at the span, cable and/or cabled segment level. The selection of the fibers may be done to meet specified optical parameters to enable fabrication of a span, cable, or cabled segment with specific parameters for a standardized application, rather than for a specific customized customer order.
The selection of optical fiber reels from inventory for use in a submarine application, to fill a customer order, has typically been accomplished by two methods. A first method has been to manually select optical fiber reels from a spreadsheet (which contains various optical parameters on each optical fiber reel), such that the selected optical fiber reels, when combined, meet the customer requirements. However, manually selecting optical fiber reels from a spreadsheet is labor intensive, time consuming, seldom optimizes the optical parameters of the combined optical fiber reels and generally fails to optimize the use of inventory. In addition, for rigorous or complex customer specifications, manual selection may not be practically possible, due to the millions if not billions of potential combinations to be considered.
Accordingly, a second method has been to select optical fiber reels from inventory using one or more computer implemented algorithms that create spans that meet customer specifications on the span level without attempting to meet or predict more rigorous upper level specifications (e.g., path specifications). However, even when computer algorithms are used, the algorithms themselves may fail to take into account various complicating factors that may arise when attempting to select optical fiber reels to fill a large or complex customer order, especially an order with rigorous customer specifications.
For example, when selected optical fiber reels are actually spliced together by a customer for implementation into a system, the measured value of one or more optical parameters may be different than predicted or theoretical value(s) when the system was originally designed (e.g., because of dispersion non-uniformity, spice losses, or environmental effects), which can shift cumulative cable, cable segment and/or path optical parameters. As a result, the requirements for cables, and/or cabled segments yet to be added to the cabled system may need revision in order for the system as a whole to meet customer or standardized requirements. In the meantime, the available inventory of optical fiber reels will have almost certainly changed since the time when the system was originally designed.
Thus, what is needed is a system and method for selecting optical fiber reels from inventory that provides the desired performance characteristics in the face of increasingly rigorous and complex customer specifications, eliminates manual selection of reels, and accounts for the possibility that actual values of optical fiber implemented into a cabled system may be different than predicted values when the system was designed, while efficiently using inventory.